Furnace divider plates



NOV. 20

4 3 1. 3 B IT; I aw INVENTOR FRANK BoRoN Nov. 20, 1962 F. J. BORON FURNACE DIVIDER PLATES 4 Sheets-Sheet 2 Filed June 15, 1960 Nov. 20, 1962 F. J. BORON FURNACE DIVIDER PLATES 4 Sheets-Sheet 3 Filed June 15, 1960 48 a5@- Mn 8 INVENTOR. FRANK J. BoRoN BY Nov. 20, 1962 F. J. BORON FURNACE DIVIDER PLATES 4 Sheets-She'et 4 Filed June 15, 1960 all This invention relates to divider plates for an orcprocessing furnace of the kind used to sinter and consolidate finely divided ore material or other metal-containing material such as finely divided iron ore or the like.

In ore-processing furnaces of this kind charges of the material to be processed are introduced through the top of the furnace, and air for sustaining combustion during sintering the metal-containing material is introduced into the furnace through tuyeres at the bottom thereof. The air thus introduced flows upwardly through the furnace and reacts with the material in process to develop the necessary high temperatures required for the sintering operation. In the course of the sintering operation th material within the furnace gradually moves downwardly therethrough with additional charges of finely divided material being periodically introduced through the top of the furnace.

It is desirable that the air travel freely through the material within the furnace, but it has been found that there is a tendency for the material to pack and form a hard crust at the top of the bed, which hard crust prevents the free passage of air therethrough. Ore-processing furnaces of this general kind are oftentimes equipped with divider plates which project inwardly from the side walls of the furnace for breaking up the crust thus formed in the downwardly moving material to maintain the material in a loose, unpacked condition. The divider plates are subjected to large temperature gradients between the lower and upper parts thereof and are also subjected to large vertical loadings by the burden of the downwardly moving material. The combination of these two factors has contributed to early failure and a relatively short useful life for the divider plates, thus rendering frequent replacement necessary.

In my Patent No. 2,824,730, dated February 25, 1958, there is disclosed a divider plate construction which has enabled a significant increase in the life of a divider plate to be realized. The aforesaid patent discloses a solid, one-piece divider plate having corrugations disposed parallel to the isotherms developed in the furnace. This divider plate construction has proven an eminent commercial success and is at the present time extensively used. In comparison with the art as heretofore known, the divider plate of Patent No. 2,824,730 has afforded an eleven-fold increase in divider plate life. It is a primary object of the present invention to construct a divider plate which is even more resistant to thermal abuse and early break-up than that of the aforesaid patent. Tests indicate that a divider plate constructed in accordance with the present invention will enable a three-fold or greater increase in divider plate life over that of the aforesaid patent to be achieved.

It is an object of the present invention to form the lower portion of a divider plate with a segmented construction which, while effective to maintain the material in process separated and in a loose and unpacked condition, minimizes the transfer of thermally induced stresses between the individual segments of the lower portion of the divider plate and also between these segments and the other parts of the divider plate.

In accordance with the present invention the segmented construction may take the form of a plurality of depend- 3,%4,9ti2 Patented Nov. 20, 1962 ing links connected to the upper part of the divider plate by articulated connections, as by hinged joints or the like; and this construction constitutes a specific object of the present invention.

The depending links can be arranged in one or more generally horizontally extending and vertically aligned rows, and it is a further object of the present invention to offset the links in immediately adjacent rows to mini mize the packing of the material in the spacings between individual links and consequent mechanical stresses on the links.

Preferably, the upper part of the divider plate includes a sloped upper edge effective to slice through and divide the downwardly dividing material in a manner akin to that of a knife blade. In one form of the present invention the upper part of the divider plate is a solid, onepiece member having a corrugated cross-section of substantially uniform thickness afforded by at least one alternate and generally horizontally disposed rib and groove on the opposite side faces thereof. In another form of the present invention the upper portion of the divider plate has conduit means formed internally therein for circulating cooling fluid therethrough. Divider plate constructions incorporating the foregoing structural fea tures constitute further objects of the present invention.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show preferred embodiments of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art Without departing from the present invention and the purview of the appended claims.

In the drawings:

FIG.1 is a diagrammatic top plan view of a furnace in which the present invention may be embodied;

FIG. 2 is a sectional view taken substantially along the line indicated by the arrows 2-2 in FIG. 1;

FIG. 3 is a side elevation view of a divider plate constructed in accordance with one form of the present invention;

FIG. 4 is an end elevation view of the divider plate illustrated in FIG. 3;

FIGS. 3A and 4A are respective side elevation and end elevation views of another construction for atop portion of a divider plate;

FIG. 5 is a side elevation view of a divider plate constructed in accordance with another form of the present invention;

FIG. 6 is an end elevation view of the divider plate illustrated in FIG. 5

FIG. 7 is a section View taken substantially along the line indicated by the arrows 7-7 in FIG. 10;

FIG. 8 is a sectional View taken substantially along the line indicated by the' arrows 6-3 in FIG. 10;

FIG. 9 is a sectional view taken substantially along the line indicated by the arrows 9-9 in FIG. 10;

FIG. 10 is a side elevation view of another form of a divider plate constructed in accordance with the present invention;

FIG. 11 is an end elevation view taken in the direction of the arrows 11-11 in FIG. 10;

FIG. 12 is a fragmentary view taken. in the direction of the arrows 12-12 in FIG. 10;

FIG. 13 is a fragmentary end elevation view taken in the direction of the arrows 13-13 in FIG. 10; and

FIG. 14 is a sectional view taken substantially along the line indicated by the arrows 14-14 in FIG. 10.

In FIGS. 1 and 2 there is shown diagrammatically a furnace PR of the kind with which the present invention is concerned. The furnace PR is constructed of refractory brick and includes vertical side walls and 11, vertical end walls 12 and i3, and a bottom wall 14. The bottom wall 14- is provided with an opening 16 of the usual kind through which a blast of hot air is introduced into the furnace from tuyeres to produce the heat in the furnace cavity.

The finely divided ore material that is to be exposed to the heat is introduced at the top of the furnace, and under the present invention the side walls lit and 11 at the upper portions thereof are provided with a plurality of inwardly directed divider plates 21 which maintain the top of the bed B of the material undergoing heat treatment in a continuous collapsed, that is, loose condition so that any tendency for the material to coalesce or fuse into a cake or crust is prevented. This assures a free, uniform How of hot air upwardly through the furnace and breaks up the material in the furnace so that the material is uniformly heat treated.

The divider plates 24 in the present instance are produced as castings, and because of the high temperatures encountered these castings consist of a heat-resistant alloy. 1 have found that a highly alloyed steel containing 24 percent chromium, 12 percent nickel, 0.30 percent carbon, and the remainder essentially iron gives highly satisfactory performance. This alloy is extremely strong and ductile, consistent with the mechanical and thermal stressconditions encountered in a furnace as FR. Chromiurn may vary from '20 to percent; nickel from 10 to 20 percent; carbon from 0.20 to 0.46 percent; remainder substantially iron.

As shown in FIG. 2, the upper side edges of the furnace FR are bevelled. The plates 20 are adapted to be secured to these bevelled faces of the furnace PR, and to this end are formed with hanger brackets 21 adapted to receive fastening bolts 248. The bolts 24B serve to anchor the plates 20 securely in place with the plates extending inwardly of the side walls of the furnace, that is, in normal relation compared to the side walls of the furnace. The divider plates indicated generally at 20 in FIG. 2 may be of any of the specific forms to be described in detail hereinafter.

The thermal stresses to which the plates 20 are subjected are rather severe, especially when it is considered that the heat near the lower edges of the plates 20 may exceed 2000 F. under certain conditions, and under these same conditions the temperature at the top of the material bed just above the upper edge of the plates may be less than 500 F. In FIG. 2 the variations in the temperatures in various parts of the material in process are diagrammatically indicated in a very general manner by isotherms 1-1 and L4 in which the higher numbers indicate higher temperatures. It will therefore be seen that the temperature differential between the upper and lower edges of the plates 20 is quite large, and such severe temperature conditions have resulted in short life of furnace divider plates. Thus, the large temperature differentials existing between the upper and lower parts of each divider plate cause these parts to expand different amounts and develop internal stresses within the divider plates, which stresses are directly proportional to the temperature differential existing therein.

In accordance with the present invention a divider plate includesa lower portion having a segmented construction in which individual segments are separated from one another and are permitted relative movement therebetween. As will become more apparent from the description to follow this segmented construction minimizes the transfer of thermally induced stresses, both between the individual segments and the upper part of the divider plate.

One form of a divider plate thus constructed in accordance with the present invention is illustrated in FIGS. 3 and 4 and is designated generally by the reference numeral 20A. The divider plate 20A includes an upper part 31 which is of a generally triangular shape in side elevation and which includes a downwardly inclined upper surface or edge 32 for dividing and separating the downwardly moving material in process within the furnace. The upper part 31 presents a relatively narrow profile in plan view when the divider plate NA is oriented in an operative positionwithin the furnace. In this instance the upper part 31 is formed with a corrugated cross-section, as best illustrated in the end view of FIG. 4. The upper part of the divider plate has a substantially uniform thickness so that a groove as 33 in one side surface of the divider plate is presented as a rib 34 in the opposite side surface of the divider plate. The corrugations thus defined project substantially normal to the direction of downward movement of the material in process, and, as will be apparent from an inspection of FIG. 2, the ribs and grooves extend generally parallel to the isotherms within the furnace. The purpose of this corrugated configuration of the upper part of the divider plate is to facilitate the differential expansion along the vertical extent of the upper part of the divider plate, which differential expansion is caused by the temperature gradient through this part of the divider plate.

A base flange 35 is formed integral with the upper part 31 in a plane generally normal thereto, and is adapted to seat against the inner surface of a side wall of the furnace in the mounted position as illustrated in FIG. 2. The base flange 36 includes an upwardly extending part 3'7 which is adapted to function as a hanger member for fastening the divider plate ZQA to the side wall of a furnace whenever a mounting bolt as 2433 (see FIG. 2) is inserted within a rectangular-shaped slot 38 formed in the hanger member 37.

With reference once again to FIG. 2 it will be observed that the highest temperatures are developed in the lower portion of the divider plate. The divider plate 20A illustrated in FIGS. 3 and 4 incorporates a segmented lower construction in which a plurality of individual segments or link members 38A and 33B are separated and slightly spaced from one another so as to be free for thermal expansion and relative movement with respect to one another. Therefore, any thermally induced stresses tending to produce deformation or cracks in any one segment are localized therein and cannot be transferred to any other segment. In other words, the lower extremity of the divider plate is discontinuous and comprises isolated elements which confine the thermal stresses.

In this instance the individual segments or link members 38A and 38B are also attached to the upper part 31 in articulated connections which substantially eliminate any transfer of thermally induced stresses between these segments and the upper part 31 of the divider plate. Thus, in the form of the divider plate illustrated in FIGS. 3 and 4 the individual se ments depend from the upper part 31 in two substantially horizontally extending and vertically aligned rows. The segments 33A are attached by a hinge connection to the upper part of the divider plate while the segments 385 in the lower row are attached by a hinge connection to the lower ends of the segments 38A. Thus, the lower edge of the upper part 31 of the divider plate is formed with a number of hinge knuckles 39, and each of the segments 38A includes an eyelet 41 interposed between a corresponding pair of hinge knuckles 39. A pin 42, which is preferably a cast member of heat-resistant alloy rather than a forged member, is suitably retained in axial position Within the hinged knuckles 39 as by being welded at W to a hinge knuckle 39. Eyelets 43 are formed on the lower ends of the link members 38A and fit between hinge knuckles 44 formed on each of the segments 3813. A pin 46, which is also preferably cast like the pin 42, completes the hinge connection between the link members 38A and 38B and is retained in axial position as by welds W1.

In the form of the divider plate illustrated in FIGS. 3 and 4, each of the segments 38A and 33B is slightly spaced from an adjacent segment, and the eyelets 41 and aoeaeez 43 are permitted some axial movement with respect to the respective hinge knuckles 39 and 44 so that thermal expansion without binding is permitted for all temperature conditions that may occur in the course of operation of the furnace.

In operation the upper part 31 of the divider plate 29A functions as a blade member for slicing through and dividing the downwardly moving material, while the articulated and segmented lower portion of the divider plate ZhA forms a downwardly extending continuation of the upper part of the divider plate and is effective to maintain the divided material in a loose, unpacked condition.

The benefits obtained from the segmented construction are at least three-fold. As noted hereinabove, the transfer of thermally induced stresses from any one individual segment to any other part of the divider plate is effectively m nimized. Thus, for this reason alone the divider plate A is capable of a great deal of thermal abuse since free relative thermal expansion and contraction of the upper and lower parts of the divider plate without cracking therebetween is permitted.

Additionally, the divider plate 20A can effectively perform its function even though a part thereof should be damaged or lost. Thus, in the form of the divider plate illustrated in FIG. 3, the divider plate 20A can function effectively even though up to three segments as 38A or 383 should be lost in either or both rows.

The divider plate ZllA also achieves economy in operation inasmuch as the upper part 31 will generally last longer than the lower portion. Therefore, the divider plate ZilA can be periodically removed from the furnace and the upper pmt 31A fitted with replacement segments as 38A and 3813.

In FIGS. 3A and 4A there is illustrated a modified and substantially planar upper part of a furnace divider plate which can be utilized when the temperature conditions within the furnace are not so severe as to require a corrugated configuration like that illustrated in FIGS. 3 and 4. Except for the absence of ribs and grooves, the divider plate part illustrated in FIGS. 3A and 4A is like the part 31 incorporated in the divider plate illustrated in FIGS. 3 and 4, and like reference numerals are used to designate like parts but with the addition of the suffix A in FIGS. 3A and 4A. Thus, the part 31A has an inclined upper edge 32A and planar side walls 35. Also, the lower edge of the part 31A is formed with a series of hinge knuckles 39A for the attachment of segments like those illustrated in FIGS. 3 and 4.

in the form of the divider plate illustrated in FIGS. 3 and 4 the segments 33B are disposed substantially directly beneath corresponding segments 38A.

In some instances it may be desirable to offset the segments in one row with respect to the segments in another row to minimize the tendency for the material in process to become packed within the spacings between the segments or link members. This construction is illustrated in FIGS. 5 and 6. With the exception of the above-noted olfsetting of the individual segments or link members in one row with respect to those in another row, the divider plate illustrated in F168. 5 and 6 is generally similar to that illustrated in FIGS. 3 and 4, and like reference numerals, but with the addition of the prime mark in FIGS. 5 and 6, are used to designate like parts. Thus, in the construction illustrated in FIGS. 5 and 6 the lower row comprises alternate segments 38C and 38D. Each segment 38C is approximately half again as wide as a related segment 38A in the upper row and is formed with a pair of hinge knuckles 43 which receive an eyelet 43 therebetween. Each segment 381) is approximately the same width as a segment 38A and includes an eyelet 49 which fits between a pair of eyelets 43' and which is aligned with the spacing between the respective segments 38A. Thus, the spacings between the segments 38C and 38D are offset from the corresponding spacings between the segments 38A to minimize the tendency of the material in process to become wedged and packed therein, and

5 articulation of the individual segments is thereby enhanced.

A third form of a divider plate constructed in accordance with the present invention is illustrated in FIGS. 7-14 and is designated generally by the numeral 51. In this instance the upper part of the divider plate is adapted to have cooling fluid circulated therethrough. Thus, the upper part of the divider plate includes peripheral, generally tubular-shaped conduit structure which defines a substantially triangular-shaped upper part, as illustrated in the side elevation view of FIG. 10. The tubular-shaped conduit structure includes avertically disposed leg 53 integrally joined with a hanger member 54 and a base flange 56. The leg 53 joins with a generally horizontally extending leg 57, which in turn merges into leg 58 at the forwardmost end of the divider plate 51 to define a hollow nose portion in that area of the plate. The leg 53 extends upwardly from the forwardmost end of the divider plate to the hanger member 54 and affords an upper inclined surface 59A and 583 effective to slice through and divide the downwardly moving material in process in the same manner as the corresponding surfaces of the other forms of the divider plate of the present invention. A web 61 extends between and joins the legs 53, 57, and 5% but is formed with openings a2 and 63 in the corners defined by the merger of the legs 53 and 57 with the leg 58. These openings 62 and 63 alleviate the build-up of stress concentrations in these areas. if desired, the web 61 can be formed with a similar opening in the corner defined by the juncture of the legs 53 and 57. This part of the divider plate is preferably formed by casting, and as illustrated in the respective FiGS. 7, 8, and 9 and 14, the wall thicknesses of all portions of the upper part of the divider plate, including the web 61, are of substantially uniform thickness to thereby minimize problems of differential thermal expansion.

With particular reference now to H65. 9, 11, and 12, it is seen that the hanger member 54 is formed with two internal passageways 6i and 62 separated by a Web 63. The passageway 51 constitutes an inlet passageway which communicates with a passageway 64 defined by the hollow interior of the leg 53 (see FIG. 8). The passageway 62. affords an outlet passageway in communication with passageway 66 defined within the leg 58 (see FiG.ll).

As illustrated in MG. 7, the leg 57 includes a passageway 67 defined within the hollow interior thereof, and this passageway 67 communicates with the passageway 64 in the le 53 and also with the passageway as and leg 58 through a chamber 68 defined within the hollow interior of the forwardmost part or nose of the divider plate 51 (see FIG. 14). Thus, air or other cooling fluid can be introduced through the passageway 61 and circulated throughout the tubular frame of the upper part of the divider plate by means of the conduit structure described above. Thereafter, the cooling fluid is removed from the divider plate through the outlet passageway 62. It should also be noted that the construction illustrated in FIGS. 7-14 enables air lines or the like to be directly attached to the uppermost end of the hanger member 54 so that there is little chance for the connections to be damaged by the material in process.

The hanger member 54 is formed with a rectangularshaped slotted opening 71 which is adapted to receive a fastening bolt like the bolts 24B illustrated in FIG. 2.

In the form of the divider plate illustrated in FIG. 10 only a single row of segments or link members is shown attached to the upper part of the divider plate. However, additional rows could be added by arrangements similar to those illustrated in FIGS. 35, if so desired. In the form of the divider plate illustrated in FIG. 10, the lower edge of the upper part of the divider plate is formed with a series of hinge knuckles 72, and the individual segments 70 are each formed with an eyelet 73 retained in position between the knuckles 72 by a pin 74. As in the other illustrated embodiments of the invention, the pin 74- is '2 preferably cast and is welded in position by weldment W2.

Thus, in accordance with the present invention there are provided several forms of divider plate constructions which are especially adapted to absorb a large amount of thermal abuse in ore-processing furnaces of the general kind described and still remain effective to function in the manner desired. Each form of the divider plate of the present invention incorporates a segmented lower portion substantially coplanar with the upper portion and in which the individual segments are spaced from one another to minimize the transfer of thermally induced stresses therebetween. Additionally, each segment is connected to an upper part of the divider plate in an articulated connection and may be readily removed therefrom. The upper part of the divider plate may be formed with a corrugated configuration for facilitating ditierential thermal expansion, or may be adapted to have cooling fluid circulated internally therethrough.

Hence while I have illustrated and described the preferred embodiments of my invention, it is to be understood that these are capable of variation and modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. A divider plate for an ore-processing furnace of the kind in which the material in process is introduced through the top of the furnace and moves progressively downwardly therethrough during the processing operation, said divider plate being adapted to project inwardly from a side wall of the furnace into the material in process in the furnace and comprising an upper blade member having a generally right triangular configuration in side elevation when oriented in an operative position in the furnace, which configuration is defined by a substantially vertically extending rear edge adapted to seat against the side wall of the furnace, an inclined upper edge inclined forwardly and downwardly from the rear edge and eifective to slice through and divide the downwardly moving material, and a substantially horizontally extending lower edge, said divider plate comprising also a lower segmented portion which includes a plurality of individual platelike link members arranged in horizontally extending and vertically aligned rows and depending from the lower edge of the blade member substantially in a front-to-rear row and substantially in the plane of the blade member, and means affording articulated connections between said link members and said blade member for minimizing the transfer of thermally induced stresses between the individual link members and between the link members and the blade member.

2. A divider plate as definedin claim 3 in which a first row of link members is directly connected to the lower edge of the blade member in' a hinge-type joint and a second row of link members is connected to said one row in another hinge-type joint, and in which the link members in the second row are horizontally ofi'set with respect to the link members in the first row.

3. A divider plate for an ore-processing furnace of the kind in which the material in process is introduced through the top of the furnace and moves progressively downwardly therethrough during the processing operation, said divider plate being adapted to project inwardly into the material in process in the furnace and comprising an upper portion substantially of solid blade-like construction having a lower extremity and a substantially vertically straight rear edge extremity and formed with an upper surface inclined downwardly from the rear edge for slicing through and dividing the downwardly moving material, and a lower segmented portion substantially in the plane of the upper portion including a plurality of individual one-piece plate-like segments separated from one another in a front-to-rear row and pivotally connected in dividually to the lower extremity of said upper portion for minimizing the transfer of thermally induced stresses between the individual segments.

4. A divider plate for an ore-processing furnace of the kind in which the material in process is introduced through the top of the furnace and moves progressively downwardly therethrough during the processing operation, said divider plate comprising an upper member substantially of solid blade-like construction presenting a relatively narrow profile in plan view when oriented in an operative position in the furnace and having a lower extremity and a substantially vertically straight rear edge extremity and formed with an upper surface inclined downwardly from the rear edge for slicing through and dividing the downwardly moving material, a lower segmented portion which includes a plurality of individual plate-like link members depending from and substantially in the plane of the upper member and arranged substantially in a front-to-rear row, and means affording articulated connections between said link members and the lower extremity of said upper member for minimizing the transfer of thermally induced stresses between the individual link members and between the link members and the upper member.

Shea June 14, 1955 Boron Feb. 25, 1958 

